June 10 (HealthDay News) -- Diabetics getting weekly injections of an experimental long-lasting version of the drug exenatide lowered their glucose levels and lost weight over the year they were on the medication, a new study reports.

The new drug, dubbed "exenatide once weekly," even appeared to cause additional improvements in A1C (glycated hemoglobin) and fasting plasma glucose in diabetics currently receiving twice-daily injections of Byetta -- the version of exenatide now on the market.

The findings, overseen by the three pharmaceutical companies developing exenatide once weekly, were presented this week at the American Diabetes Association annual meeting, in San Francisco.

"Patients significantly reduced their blood glucose levels and, on average, lost a total of over 9 pounds. These improvements were sustained for a year," Dr. John B. Buse, director of the Diabetes Care Center and chief of the division of endocrinology at the University of North Carolina School of Medicine in Chapel Hill, said in a prepared statement. "Importantly, the study results also showed that steady-state levels of exenatide may result in improvements in a variety of glucose parameters. If approved, exenatide once weekly may provide patients with a treatment option that is on board 24 hours a day, seven days a week, helping to manage their blood sugar and, secondarily, their weight."

Byetta is sometimes used to complement other glycemic-control medications, such as metformin, a sulfonylurea, or a thiazolidinedione, in people with type 2 diabetes. Byetta is the only incretin mimetic approved by the U.S. Food and Drug Administration for use by type 2 diabetes who are otherwise unsuccessful at controlling their blood sugar levels.

The study, which included almost 300 type 2 diabetics, showed that those taking exenatide once weekly over the course of one year or for just 30 weeks lowered their A1C by average of 2.0 and their fasting plasma glucose (FPG) by 47 mg/dL.

In the open-label study, 295 patients with type 2 diabetes received subcutaneous injections of either exenatide once weekly or Byetta twice daily for 30 weeks. Following this, 258 patients either remained on exenatide once weekly or switched from Byetta to exenatide once weekly for an additional 22 weeks.

After 52 weeks, 74 percent of all patients achieved an A1C of 7 percent or less -- the target the ADA recommends for good glucose control. Patients in both groups experienced an average loss of 9.5 pounds over the year.

Subjects using exenatide once weekly experienced minor side effects, such as mild nausea. Minor incidents of hypoglycemia occurred in patients using sulfonylurea therapy.

Amylin Pharmaceuticals Inc., the maker of Byetta, is working with Eli Lilly and Co. and Alkermes Inc. to develop exenatide once weekly.

More than 21 million people in the United States and an estimated 246 million adults worldwide have diabetes, according to statistics. Diabetes is the fifth leading cause of death by disease in the United States.

SOURCE: Amylin Pharmaceuticals Inc., Eli Lilly and Co., Alkermes Inc., news release, June 9, 2008